Quick note:

We’ve released Planning v3.1.1, Tasks Plus v3.0.5 and Quick Add Plus v3.1 for activeCollab 3. All three are recommended upgrades for activeCollab 3 users. Please download them from our “My Account” area.

You don’t need to “uninstall” and “reinstall” to upgrade. Simply overwrite the module folders on your server, login as admin, and rebuild images, clear cache and clear compile folders using “Admin Tools” in activeCollab bottom bar menu.